Datasheet, most probably, for the 2sa1952 transistor, in a 60.4 KB PDF indexed as a schematic. The 2SA designation comes from the Japanese JIS system and indicates a PNP bipolar part. Open it in a PDF reader to check lead assignment, the package outline, voltage and current ratings, and gain classifications when replacing a faulty transistor or evaluating a substitute. The name contains only the part number, so verify the marking on the original component.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @cyberlanelectonik. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.
Any PDF readerSumatraPDFFirefox / ChromeFlexBV (links PDF to boardview)